Such devices as a router and a network switch generally consist of a line card circuit on a line card board and a switched fabric circuit (abbreviated as fabric circuit), for example, a fabric application-specific integrated circuit (fabric ASIC), on a switched fabric board (abbreviated as fabric board). To implement a nonblocking cross-connect between line card circuits and switched fabric circuits in the router or the network switch, the line card circuits and the switched fabric circuits need to be fully interconnected to each other.
Generally, for the router and the network switch, a backplane is used to implement an interconnection between the line card circuit and the switched fabric circuit. FIG. 1 is a schematic diagram of a backplane that implements a full interconnection between the line card circuits and the switched fabric circuits. The backplane illustrated in FIG. 1 provides three connectors, that is, a connector S1, a connector S2, and a connector S3, connected to the switched fabric circuit; and three connectors, that is, a connector L1, a connector L2, and a connector L3, connected to the line card circuit. Any connector connected to the switched fabric circuits on the backplane is connected to all connectors connected to the line card circuits. Similarly, any connector connected to the line card circuits on the backplane is connected to all connectors connected to the switched fabric circuits. The backplane is generally produced by using a printed circuit board (PCB). Because the wires on the printed circuited board cannot be intersected, the backplane generally implements a full interconnection between the line card circuits and the switched fabric circuits by using a multilayer printed circuit board.
In FIG. 1, the line card circuit is disposed on a line card board, and the switched fabric circuit is disposed on a switched fabric board. In actual applications, the line card circuit and the switched fabric circuit may also be disposed on different boards.
As the number of desired connectors connected to the line card circuits and the switched fabric circuits increases, the number of layers and the size of the printed circuit board for producing the backplane increase linearly. A common printed circuit board process may not meet the requirement for a backplane that provides a great number of connectors.